Oscillation-generatqr



L. DEFOREST.' OSCILLATON GENERATOR. l APPLICATION'FILED SEPTA. |915. 1,31 1,264, n Patented July 29, 1919.

5 SHEETS-SHEET 2.

LDB FOREST; OSCILLATION GENERATOR.

. l Patented July 29, 1919.

5sHETs-sHET 4 Nunn ttozwzif A Y m( l? ,aff

L. DE FOREST. OSCILLATION GENERATOR. APPLICATION FILED SEPTA. I9I5.

Patented July 29, 1919.

5 SHEETS-SHEET 5.

'UNITED STATES PATENT OFFICE.

LEE ma FOREST, F SPUYTEN DUYVIL, NEW YORK, ASSIONOR TO DE FOREST RADIOTELEPHONE AND TELEGRAPH COMPANY, 0F NEW YORK, N. Y., A CORPORATION OFDELAWARE.

OSCILLATION-GENERA'TOR.

Patented July 29, 1919.

Application led September 4, 1915. Serial No. 48,948.

To all whom it may concern.'

Be it known that I, LEE mi FOREST, a citi- Y i zen '.ofl the UnitedStates, residing at Spuyten Duyvil, in the county ofBronX, State of `NewYork, have made a certain new and useful Inventionl inOscillation-Generators, of which the following is a specification.

This invention relates to oscillation en- I erators of the normallyoscillating au ion y methods, which are simple and eiicient andtypewhichl will designate oscillions.

The object of the invention is to pro` vide apparatus, circuitarrangements and wherein the oscillation energy generated in the devicesof the type referred to is greatly increased, altered or varied.

Other objects of the invention will be more fully hereinafter set forth.

The invention consists substantially in the construction, combination,arrangement and mode of operation, all as will be morel fullyhereinafter set forth, as shown in the accoml panying drawings, andfinally pointed out in the appended claims. v

`Referring to the drawings Figures l to l0 are circuit diagrams showahot electrode and two cold electrodesyone interposed between the hotelectrode and the other, or, in other words, placed at relativelydifferent distances from the hot electrode.

Ihave found that in radio telephone and telegraph transmitter generatorsofthe oscillation type, that is, of the oscillating audion type in whichelectrode elements are sealed within a closed vessel, the amount ofoscillating energy generated may be greatly increased altered, or variedby impressing, in accordance with the signals to be transmitted,relatively small, slowly changing differences fof potential uponelectrode ele-V ments sealed within the closed vessel. These electrodes'upon which the relatively small and slowly changing potentials areimpressed may be the same as thoseemployed or concerned in the high`frequency generatf ing system, or they may be independent of 4hausted ofair, orpartiall manner.

generated high frequency oscillation.

the oscillating circuit electrodes, or somemay be independent Vandothersthe same electrodes employed inthe high frequency generation.

t In the circuit diagram of Fig. l 'I havel shown an oscillion employinga closed vessel 1, which, preferably, is evacuated or eX- so, with thewing or cold plate electro e2, 2, the filament or hot electrode 5, andthe grid electrode 3, 3, sealed therein in thel customary In practicethe grid electrode is interposed between the plate and filament, thoughI do not wish to limit myself in this respect.

Where two wing or plate and two grid electrodes are employed, as in theexample shown for illustrative purposes, the best, but not the onlypermissible arrangement, is to locate a grid element between each plateand the filament. r

The plate and grid elementsor electrode are connected to the oscillatingcircuit 21,l 11, 10, in the usual way, 21 being the stopping condenser,l1, an inductance-in this case the primary winding of an oscillationtransformer through which said oscillating circuit is associated with aworking circuit, and 10 a condenser, preferably adjustable, in parallelwith the inductance. It is to be understood that the oscillating circuitmay be associated in any usual and well known manner with the workingcircuit, the inductive or two-coil transformer coupling being selectedas merely illustrative of the principles involved. The working circuitymay be of any desired character for utilization of Ithe 4orillustrative purposes I have shown this cir-f c'uit-as a radiatingantenna earth circuit containing the aerial 13, the secondary 12 of thetransformer or othercoupllng to the oscillating` circuit, and the earthconnectiom'or other counterpoise indicated at 14.

In the arrangement shown wherein a plurality of plate and gridelectrodes 2, 3, are employed, the plate .electrodes are arranged inparallel in a circuit which includes the positive terminal of a suitablecurrent source 8, preferably, though notnecessarily, a -direct currentgenerator of from 509 to 1500' volts.v Thiscircuiticonnection alsoincludes the impedance or resistance 9, through which the source 8delivers its current to the' plate electrodes. Thev negative terminal ofthe current source is connected to one side of the lilament circuitwhich circuit also contains a current source 6 for heating the lilamentand a regulating or controlling resistance 7 for controlling the heatingcurrent supply to the filament.

In accordance with my invention 'I propose to control the intensity ofthe high frequency oscillation energy generated in the apparatus andcircuit arrangement above described, by and in accordance with thesignals to be transmitted. This result ,may be accomplished in a varietyof ways. In one embodiment of the idea I employ an auxiliary orindependent electrode 4, which is also sealed in the vessel 1 andsuitably associated with the signal producing element in a circuit thecurrent supply in which is varied according to the signals to be` sent.The auxiliary or control electrode may have any suitable or desiredlocation within the vessel 1 and if independent of the oscillionelectrodes may bear any desired relation with reference thereto. In theform shown in Fig. 1, where two plate and twogrid electrodes are used, Ialso employ two auxiliary or independent, or what'I shall call controlelectrodes', one located between the plate and grid electrodes on oneside of the filament and one between the plate and grid electrodes onthe other`side of the -lament. As'above stated, however, my invention isnot to be limited or restricted to this relation and arrangement. Wherethe two control electrodes are employed, as shown in Fig. 1, they areconnected in parallel to each other in a circuit which includes inseries therein the filament 5. This circuit is associated with thesignal producing means,

shown in this instance, and for illustrative y purposes, as a microphone18. The circuit Y of the microphone contains the usual battery or othercurrent source 17, and may be associated with the circuit of the controlelectrode or electrodes in any desired or well known manner. A simplearrangement is shown wherein an inductive couplin is secured Athroughthe coils 15 and 16 1n said respective circuits. If desired a condenser19 of relatively large capaci-ty is includedin the circuit of thecontrol electrodes.

lIt will be seen .that by the arrangement described changes of potentialvarying in accordance with the signals to 4be transmitted are impressedupon the auxiliary or control electrodes and the filament, and

Iso'

where the microphone is employed asthe signal producing device, thepotential variations impressed upon they control electrodes andfilament, respectively are voice controlled.

I haveI discovered that when potential variations are thus impressedupon the elements in the vessel, corresponding but greatlyampliedalteration in the ampliiineea In Fig. 2, I have shown a slightlymodi-y fied arrangement wherein a single plate 2, and a Single grld Bareused, and wherem the control electrode 1s 1n the form of two members4ta, having intermeshing fingers vand respectively connected to theterminals of the coil 15. In other respects the vcircuit connections ofthe various elements remain the same as abovedescribed with reference toFig. 1.

Another .arrangement embodying the prin- 7" ciples of my invention isshown in Fig. 3, 1n which the worlrlng circuit '1s omitted. In thisarrangement, however, the control electrodes 4, 4, are located betweenthe grid elec- A trodes 3 and the filament 5. The two control electrodesare respectively connected to the terminals of the coil 15, as in Fig.2, but the central orneutral point of this coil is connected to one side oi the filament circuit. In this manner a positive potential isimpressed upon one of the control electrodes 4 at the same time anegative potential is impressed upon the other of said controlelectrodes, by

the operation of the signal producing device, while normally a constantpotential is equally impressed upon both of said electrodes, which maybe that of one of the terminals of the filament, preferably the negativeterminal, or the constant potential normally supplied to both controlelectrodes may be derived from a battery or other current sourceindicated at 30. By thus varying the normal potential of the controlelectrodes in correspondence with the signals to be transmitted, and inconformity with conditions obtaining in 'the vessel 1, theeli'ectiyeness of the ampllfication of the generated increased. Thus,where the oscillation is a large one operatlng energetically Linder highimpressed potentials between the electrodes ,-2, 2, and 5, it isadvantageous-to increase the constant potential impressed upon the con-)trol electrodes, and this can/.be accomplished by employing theadditional source of po` tential 30.

In Fig. 4 I have` shown another arrangetion wherein; is employed whatmay be independent electrodes. 1 In this arrangement a grid .3 isconnectedl through the high frequency oscillations is very greatly mentVembodying the principles of my inven- .termed a double or compoundoscillion with oscillating circuit 21,11, 10, to the wing or.

plate 2, but with the grid 3 located within Viating Circuits 21, 11; 10,and 21A, 11A, and 10A,

are ordinarily tuned alike through the condensers 21, and 21A, and saidcircuits are respectively associated with the working circuit. Thislassociation may be accomplished 1 in any suitable or convenient manner,as,

for example, inductively through the Windings 12, 12A, which may bearranged in series in the working circuit, such as `the antenna earthcircuit 13, 14. A direct cur# rent of high voltage is supplied to eachplate electrode 2, 2A, as, for example, from the sources 8, 8A, throughthe impedance or choke coils 9, 9A, the positive terminals of thecurrent sources 8, 8A, lbeing connected to the plates 2, 2A; Thisarrangement of double or compound oscillion I have -found in practice tobe highly-.eicient in the generation of high frequency oscillations.While I have shown two independent sources 8, 8A, of di# rectcurrent'supply for the plates 2, 2A, independent sources are notessential though preferable, .In the operation of the compound osc1ll1onarrangement oshown oscillations in one oscillating circuit react fromAits associated pair of electrodes, through the other pair ofelectrodes'to the oscillatingcircuit containing the latter, with theresult that a more energetic oscillation generation ltakes place in eachoscillating circuit than would be the Vcase if the other circuit isomitted. 'In other words the presence of one of said oscillatingcircuits with its associated electrodes in the relation explainedincreases the generating action of the other oscillatin circuit withvlts association and relation o electrodes, the'combined and increasedeliect of the two sets'of oscillations, the circuits being in `.tunewith eachother, being obtained in the working. circuit.

, In Fig. 5 I have shown a slightly modified arrangement of the compoundoscillion, but having the same mode of operation. In this arrangementeach grid 3, 3A, is juxtaposed withreference to the late 2, 2A, of itsown oscillating circuit, an withinthe iniuence of its ownassociatedplate and the filament. In this arrangement I have also showna common source of high voltage direct current 8 for the two plateelectrodes-2, 2A, but with a separate choke coil or impedance in eachlead from the common source 8, as indicated iat 9, 9^. The mode ofoperation of this arrangement is the same as-hereinbefore described.Oscillations in one oscillating eircuit react from one pair ofelectrodes to the other pair upon the other oscillating circuit, and thecombined effect of the two sets of yoscillations is obtained inthe loadcircuit In Fig. 6, I have shown two oscillation generators similar tothe one shown in Fig.

l, each containing the auxiliary `electrodes v Llhe wingelectrodes 2,2A, 'of these two oscillations are supplied with currentLpreferably ofhigh 'voltage and direct current such as from source 8, andtheir twofilaments 5 and 5A in series with the common 'heating battery 6,controlled by the common rheost-at 7. The two control electrodes 4, 4A,are connected to a common secondary coil 15, of a transformer of thesignal circuit, so that positive potential is impressed on one systemwhile negative potential is impressed on--the other. The neutral orcenter point of the coil 15, may be connected to the common filavmentlead 36, and a constant potential may be impressed Iupon each controlelectrode through a battery 30 if desired, but ymy invention is not tobe limited in this respect.

In` Fig. 7, I have shown two oscillions l and 1A., the filaments ofwhich are connected in parallel to a common heati'n battery 6. rfhe wingand grid electrodeso 1 arevconnected to the, oscillation circuit 10, 11,21, in the manner hereinbefore described, while the wing and gridelectrodes of l1A are con# nected to the oscillation circuit 10A,11A,and

21A, the two coils 11 and 11A of the respective above named circuits,being inductively associated with a common radiating' or load system 13,14. In this arrangement I proy pose to employ a high resistance leakpath indicated at 41 and 41A, respectlvely connecting the grids 3, 3,and 3A, 3A, to one of the common'ilament battery terminals.

The grids of each oscillion are connected through choke coils 40 and40A, and condensers 42 and 42A, respectively, to one terminal ofthesecondary winding of the transformer 15, the primary of which isincluded in the signal device circuit in the usualmanner.` The wingelectrodes of the two oscillions arey supplied through impedance coils 9and 9A, with electromotive force from a'sou'rce of high voltage, such asa direct currentn generator indicated at 8.

When this arrangement is to be used for l radio telegraphy, I prefer toinsert a signal-v ing key or switch 49 in the common grid. lead, and, inthis case, to omit the stopping condensers 42 and 42A, so that the gridelectrodes may be given the potential of one leg of 'the filament, orinsulated therefrom in accordance with the telegraphic operation of thekey or switch, that is, in accordf ancel with the signals to besent. Imay also introduce asource of electromotive force in the common gridleads referred to, 1n series with key 49, so as to impress a largernegative potential upon the grid electrodes. F or," telegraphingpurposes the high voltage source 8 may be an alternating current supply,preferably one of 1000 or 2000 c cles frequency, in which case I obtainor every completecycle one sustained train of radiated waves during thehalll .cycles in which the potential of the wing or plate velectrodesareunade positive. Y

In Fig. 8 is shown 'an arrangement wherein the high frequency energyoutput of a large oscillion 100, associated inductively or otherwise, asthrough transformer coils 11,12, with a radiating antenna system- 13,12, 14, is controlled by sound waves which are utilized to generatecorresponding undulatory currents which currents are amplified andfinally delivered to the'oscillion 100. In this Varrangement a deviceoperated 'by and in accordance with'sound waves, for

4 instance a microphone 18 is'included in a circuit Acontaining acurrent source 17,l and associated "in suitable manner, as, for eX-ample, through the transformers 1'6, 15, 15A, with the grid electrodes3, 3A, of the audion ampliliersr1, 1^. Theioutput circuits of theamplifiers which contain the plate and fila-o ment electrodes 2, 5, 2A,5A, are in turn, connected to the primary. or transformer coils 50, 53,respectively. Each of these coils is associated with two independentsecondary coils,

the secondary coils 51, 52, being associated 'c plied. with heatingcurrent `from any con venient source. A current source 6 is shown forthe purpose. By this arrangement I am enabled to control very large'telephon-'ib currents with anl ordinary microphone Without danger-ofburning out orfinjuring the microphone throu vwith no lag or distortion.The combined eect of these powerful telephonie currents, all of whichare in perfectphase relation with each other provided the impedancecharacteristics of the various audions and circuits connected thereto4are made alike, is

Adelivered through secondary couplings 61', 63, 65, 67, connected u inparallel relation, to the common terminals 69, 79, one of which, sayterminal 69, is connected to the control electrodes 4 of an oscillion100. If desired, though not necessarily, a choke coil 5 4Q may beincluded in this connection. The

h excessive current, and

Larnaca other terminal 79 may be connectedto the filament system of 4theoscillion 100, as indicated'in dotted lines at 57, or it may beconnected to earth or other large capacity, as indicated at 58. Theoscillion 100 is provided with -the usual plate and grid electrodes 92,93,'and filament 95, the circuit of the 'latter being supplied fromcurrent source 96, controlled by rheostat 97, while a'source 8 of directcurrent of high voltage is connected at one terminal through imstem, andat the. other terminal'to one si e of the filament pedance 9 to theplate circuit. The grid and plate electrodes 93, 92, are connected tothe oscillating circuit 21, 10, 11, which is associated in the mannerbefore -described with the working cir- @uit 13,12,14.

By this arrangement I have found 'it possible to deliver and controlvvery vlarge' amounts of energy, or radiated energy if the workingcircuit is an aerlal-earth system,

and in -perfect consonance with the most [j delicate variations of thesmall microphone currents in the original sound-wave; controlledcircuit.

Instead of combining the magnified telephonic currents from the out-putcircuits of lthe audion amplifiers-1B, 1C, 1D, 1E, as just' so combined,to control one described,into one common circuit and using suchcurrents, oscillion, it is to -be understood that the method employedinFig. 7, may be used.

That is to say the out-put circuit of each'` amplifier 13,10, 1D, 1E, orany-'group thereof, may be connected to a separate oscillion and thenthese separate oscillions coupled up to one common radiating system orcircuit. Such an arrangement is shown in Fig. 9 where only the couplingconnections 60, 62, 64:, of the amplifier circuitsas described inconnection with the arrangement of Fig. 8, or other sources of telehonic currents, are

shown. Associated wit the couplings 60, 62, 64,' are the couplingconnections 61, 63, 65, one terminal of each of which is led through atelephone condenser'42, 42A, 42B,

. and choke coil 40, 40A, 40B, to the grid electrode 3, 3A, 3B, of theoscillions 1, 1A, 1B,"respectively.

The'other terminals of thel connections 61, 63, 65, are connected to thecommon circuit of the filaments 5, 5A, 5F, of the oscillators, whichcommon circuit, includes the usual source 6, of heating current and thecontrol resistance 7. I have here shown the wing electrodes 2, 2^, 2B,ofthe oscilla. o

tors as supplied from a common source 8 of direct current of highvoltage, through separate impedances 9, 9^, 9B, althoughit is to be"vunderstood that other of the above described arrangements may beemployed in this connection.

The -output orA oscillating circuits 21, 10,

11,21A,10A, 11132113, 10B, i12, of the oscillators are associated,inductively or otherwise,

with a common load, working, or radiating I circuit.'Inductivelassociation is shown as an illustrativearrangement, throughthe coils 11, 12,11% 12A; 11B, 12R.

Itwill be understood thatl many otherl specie arrangements,associations, and connections for accomplishing the objects and purposesabove setlforth, and for carrying my invention into'practical operation,might readily suggest themselves to persons skilled in theart withoutdeparture from the spirit and, scope of `my invention. In its broadscope, therefore, as defined in the claims, I

do not wish to be limited or restrictedto any particular arrangementshown or described.

But having now setforth the objects and naturel of my invention, andvarious arrangements' andrmethods `of .carrying the same into practicaloperationfwhatl claim as new and useful, andI of myown invention,

V and desireto secure; by Letters Patent, is

1. A source of electrical oscillating energy including an exhaustedvessel'containing one e hot and lthree cold electrodes, each of saidcold `electrodes being located at a relatively different distance fromsaid hot electrode, a work circuit, and means to transmit the generatedoscillations to said work circuit comprising circuits associated with`said 'elec-` -trodes tively dilerent Adistance `fromsaid hot eleccoldelectrodes `"being located. at a relatively 5.` Asource 'off electricaloscillating energy including an exhausted vessel containingonedifferent, distancearrom said hot electrode, the hot electrodelandfone coldeleetrode being electrically 'connectedand the other two cod electrodes beingv electrically connected to ther, aworkcircuit, andmeansto trans` miithe igeneratedoscillations to said work circuit',comprising circuits` associated with said electrodes;

4; A source of electrical :oscillating energy including an exhaustedvessel containing hot and cold electrodesfand a control electrodetherefor,l each of saidzcold electrodes beingv located at a. relativelydifferenti distance from said hot electrode, the hotelectrode and one-cold electrode being connected together and the other -9 cold l'electrode wand` said l control electrode being connected together, awork circuit, and means to transmit the generated oscillations 'to saidworkgcircuit.'

urce;ofelectrical'oscillating energy 'including an lei'zhausted vesselcontaining one hot andthree cold electrodes, each of `said l i includinganexhausted vessel containing cold electrodes being located at arelatively different distance from said hot electrode,

and an oscillating circuit connecting two of said electrodes, circuitsfor the reinainigelectrodes, a work circuit, and means to transmit thegeneratedoscillations to said work circuit com risingcircuits associatedwith all of. said electrodes. j

6. A source of electrical oscillating energy including an exhaustedvessel containing one hot and three lcold electrodes, each of said cold.electrodes being locatedat a relatively different distance from said hotelectrode,

and a' signal controlled circuit connecting two of said electrodes, awork circuit, and

means for transmitting thegenerated oscillationsto said work circuitcomprising circuits associated with Aall of said electrodes.

7 A source of electrical oscillating energy including an exhausted.vessel containing one hot and three cold electrodes, each of saidcoldelectrodes 'being located ata relatively i different distance fromsaid hot electrode, an oscillating circuit connecting two of saidelectrodes and a' signal controlled circuit connecting the other two ofsaid electrodes, a work circu1t,.and means for transmitting thegenerated oscillations to said work circuit. `8. source of electricaloscillating energy including an exhausted vessel containing hot -andcold electrodes and a control electrode therefor, each of said coldelectrodes and ,f

said control electrode .being located at a relatively dilferent distancefrom said hot electrodes, and a signal controlled circuit connectingsaid control electrode with said hot electrode, a work circuit, andmeans for transmitting the generated oscillations to said work circuitcomprising circuits associated with all of. said electrodes.

9. A source of electrical oscillating energy hot and` cold'electrodes,.and a control electrode therefor, each of said coldn electrodes andsaidcontrol electrode being located at -j a relatively different distancefroml said hot l electrode', and an oscillating circuit connecta orgyiIlCllldn an exhausted vessel contain- Vnig a hot an two coldelectrodes, a control electrode interposed between said coldelectrodes-,each of said cold electrodes and said f control electrodebeing located at a relativelydifferent distance from said hotelectrode,`a

work circuit, and means for transmitting `the `generated oscillations tosaid work circuit comprising circuits associated with allofysaidelectrodes. 11.- A source of electrical oscillating en- @gy`including en exhausted vessel contain4 ing hot and cold electrodes,each of said .cold electrodes being located at a relatively differentdistance from said hot electrode, and a control electrode therefor, asignal controlled circuit connecting said control electrode and said hotelectrode, and an oscillating circuit connecting said cold electrode, awork circuit, and means for transmitting the generated oscillations tosaidv work circuit.

12. An oscillator comprising an exhausted vessel containing a hotelectrode and three cold electrodes, each of said cold electrodes Abeinglocated at a relatively different dis-- tance from said hot electrode,an oscillating circuit connecting two of said cold electrodes, and asignal controlled circuit associated with the other of said electrodes,a

work circuit, and means to transmit the oscillations generated to saidwork circuit.

13. An oscillator comprising aV hot electrode, two coldv electrodes, anda control electrode, each of said cold electrodes and said controlelectrode being located at a relatively different distance from said hotelectrode, an oscillating circuit connecting one of said cold electrodesand said control electrode, and a signal controlled circuit associatedwith the other of said cold electrodes, a work circuit, and means totransmit the oscillations generated to said work circuit.

14. An oscillator comprising a hot electrode, two cold electrodes, and acontrol electrode, each of said cold electrodes and said controlelectrode lbeing locatedat a relatively diii'erent distance from saidhot electrode, a series oscillating circuit connecting one'of said coldelectrodes and said control electrode, and a signal controlled circuitassociated ,with the other of said cold cle'ctrodes through atransformer.

15. A plurality of oscillions each including two cold electrodes sealedtherein and connected to oscillating circuits, a third cold electrodealsosealed 'Within each of said f oscillions and connected to a commonsignaling circuit.

16. A plurality of oscillions each including two cold electrodes sealedtherein and connected to oscillating circuits, a third cold electrodealso sealed 'within each of said oscillions and connected to a voicecontrolled.

circuit.

17. Ai plurality of oscillions each includving a hot electrode and threeseparate cold electrodes' sealed therein, and a common source lofcurrent supply for said hot electrodes, a work circuit, and means fortransmitting the generated oscillations to said work circuit comprisingcircuits associated with said electrodes.

18. -A plurality of oscillions each includ` ing a hot electrode andthree separate cold electrodes sealed therein, und a common trodes, eachof .said cold electrodes being connected to an oscillating circuit, awork source of current supply for saidhot elec- Y circuit, and means fortransmitting the 20. A plurality of oscillions,\- each including a hotelectrode and a-plurality of cold electrodes sealed therein, and 'acommon source of current supply for said hot electrede, each of saidcold electrodes. bein connected to a series oscillating circuit, an acontrol electrode separate from the other electrodes of. said oscillionalso included in each of said oscillions, said control electrodes beingconnected to a. signaling circuit.

21. A-plurality of oscillions each including a hot electrode and aplurality of cold electrodes sealed therein, and a common source ofcurrent suppl for said liot electrodes, each of said co d electrodesbein connected to a series oscillating circuit, an an independentcontrol electrode separate from the other electrodes of said oscillionalso included in each of said oscillions, said control electrodes beingconnected to a common signaling circuit.

22. In a radio telephone system, an oscillion comprisino' an evacuatedvessel containing a hot andD three or more sets of cold electrodes, aplurality of audion amplifiers associated therewith tocontrol theoscillat' ing energy generated thereby and voice c0111- v Y trolledmeans for controlling said plurality of audion amplifiers.

23.V lila radio telephone system, a plurality of audionampliersconnected in parallel, voice controlled means for controlling saidaudion amplifiers, and an oscillion comprisin an evacuated vesselcontaining a hot and t iree or more sets of cold electrodes controlledby' each f said audion amplifiers.

24. In a radio telephone ystem, an oscillion comprising an evacua vesselcontaining a hot and three or more sets of cold electrodes, a pluralityof audions associated therewith, the output ciu'rents of said audionscontrolling the energyv generated .by said oscillion, and soundcontrolled means for controlling said plurality of audions.

25. In a radio telephone system, a plural` ity of audions connected inarallel, sound controlled means ,for contro the intake circuits of saidaudions, and an oscillion comprising an evacuated vessel containing ahot and three or more Vsets of cold electrodes controlled by the outputcircuits of said audions.

26. In a radio telephone system, a plurality of audions connected inparallel, sound controlled means for controlling the intake circuits ofsaid; audions, and an oscillion comprising an evacuated vesselcontaining a hot and three or lmore sets of cold electrodes controlledby the output circuit of each of said audions.

27. a radio telephone system, an oscillion comprising an evacuatedvessel containing a hot and three or more sets of cold elec- `trodes, anaudion associated therewith to control the oscillating energy generatedthereby, and voice controlled means for condion, sound controlled meansfor controlling the intake circuit of saidaudion, and an oscillioncomprising an evacuated vessel containing a hot and three or more -setsof cold electrodes controlled by the output circuit of said audion. c Y

30. In a radio signaling system, an oscillion comprising an evacuatedvessel containing ahot and three or more sets of cold electrodes, aplurality of -audion amplifiers,

' associated therewith to control the oscillatcontrolle means forcontrolling said plural-V ing ener generated thereby,and signal ity ofaudion amplifiers.

31. In a radio signaling system, a pluralityof audion am iers connectedin paralv prisin lel, signal contro led means fJor controlling saidaudion amplifiers, and an oscillion comcan evacuated vessel containing ahot an three or more setsl of cold electrodes controlled by each of saidaudion amplifiers. 5o 132,.In a radio signaling system, an oscillioncomprising an evacuated vessel containing a hot and three or more setsof cold electrodes, a plurality of audions associated therewith, theout-put currents of said audions controlling the oscillating energygenerated by said oscillion, and signal controlled means for controllingsaid plurality of audions. Y l

33. In a radio signaling system, a plurality of audions connected invparallel, signal controlled means for controlling the intake v circuitsof said audions, and an oscillion comprising lan evacuated vesselcontaining a hot and three ,or more sets of cold electr es controlled bythe output circuits of sai audions.

34. In a radio signaling system, a plurality of audions connectedin'parallel, signal controlled means for controlling .the intake`circuits of said audions, and an oscillion comprising an evacuatedvessel containing a hot and three or more sets of cold electrodescontrolled by the output circuit of each of saidaudions. v

35. An evacuated vessel containing a filament electrode and a coldelectrode, a second cold electrode located between the filament and thefirst cold electrode, and a third cold u electrode/located between thefilament and the second cold electrode.

v 36. A n evacuated vessel containing va filament electrode and a plateelectrode a grid electrode interposed etween the lament and the plateelectrode, and a second grid electrode interposed between the first gridelectrode land the filament.

37. An evacuated vessel containing a fila-Wy ment electrode, a pair ofplate electrodes located on opposite sides of said filament electrode, apair of grid electrodes located on opposite sides of said filamentelectrode andv interposed between the lament and the plate electrode, asecond pair of grld electrodes located on opposite-sides of saidfilament electrodel and interposed between the first pair of gridelectrodes and the filament.

In testimony whereof I have hereunto set my hand this 26th day ofAugust, A. D.,

LEE DE' FOREST.

